Genetically modified organisms and recombinant DNAEdexcel International A Level Biology: Flashcards

Exam questions on Genetically modified organisms and recombinant DNA

1. A biotechnology company makes human insulin using the bacterium Escherichia coli. The insulin gene is cut from human DNA using a restriction endonuclease. The same enzyme is used to cut bacterial plasmids. The fragments are mixed and joined, and the resulting recombinant plasmids are put into bacteria that are then grown in large fermenters.
   Suggest two advantages of using genetically modified bacteria to make insulin rather than extracting insulin from pig pancreases.2 marks
2. A research group produces goats that secrete human antithrombin (a protein that prevents unwanted blood clotting) in their milk. The antithrombin gene is joined to a promoter that is active only in mammary gland cells, and the recombinant DNA is injected into fertilised goat eggs, which are then implanted into surrogate mothers.
   Suggest two advantages of making antithrombin in the milk of GM goats.2 marks
3. Researchers want a tobacco plant to make a human antibody for use as a drug. They cut the antibody gene from human DNA and the T-DNA region of the Ti plasmid of Agrobacterium tumefaciens with the same restriction endonuclease. The T-DNA also carries a gene for resistance to the antibiotic kanamycin. Leaf discs are infected with the recombinant Agrobacterium and grown on a medium containing kanamycin, and plants are regenerated from the discs that survive.
   Describe how the antibody gene is inserted into the Ti plasmid.3 marks